Java加總List<Integer>及int[]array陣列中全部元素值的方法如下。
import java.util.*;
public class Main {
public static void main(String[] args) {
List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5);
int result = sum(intList);
System.out.println(result); // 15
// Java 8
result = intList.stream().reduce(0, Integer::sum);
System.out.println(result); // 15
result = intList.stream().mapToInt(e -> e).sum();
System.out.println(result); // 15
// --------------------------------------------------
int[] ints = {1, 2, 3, 4, 5};
result = sum(ints);
System.out.println(result); // 15
// Java 8
result = Arrays.stream(ints).sum();
System.out.println(result); // 15
}
public static int sum(List<Integer> intList) {
if (intList == null || intList.size() == 0) {
return 0;
}
int sum = 0;
for (int n : intList) {
sum += n;
}
return sum;
}
public static int sum(int[] ints) {
if (ints == null || ints.length == 0) {
return 0;
}
int sum = 0;
for(int n : ints) {
sum += n;
}
return sum;
}
}
沒有留言:
張貼留言